Derby Talk

Derby Talk is a forum for Pinewood Derby, Awana Grand Prix, Kub Kar Rally, Shape N Race Derby, Space Derby, Raingutter Regatta and other similar races where a child and an adult work together to create a race vehicle and a lot of fun and memories

gpraceman wrote:I think it would be harder to use parallels for axle hole drilling. I have a set of parallels and they are only 1/4" thick.

If you clamp a body between two 6X1.875X1/4" parallels with the body squared to the 6" side, then parallels would work fine for non-cambered holes. Used with a fence of even very short height and set of small 1/64" increment drills used as spacers, they would drill cambered holes reliably.

1-2-3 blocks would need to be used in pairs in the form of a 1-2-6 block. A single block would require clamps with about 2-1/2" deep throats to secure the block and body and the pressure of the drill would be far off the end of the 3" block dimension, requiring special effort to keep the block square.

gpraceman wrote:
I think it would be harder to use parallels for axle hole drilling. I have a set of parallels and they are only 1/4" thick.

Randy,

Thanks for the clarification. In regard to using them to drill axles holes, as Stan just pointed out you can clamp the block between two Parallels and they work very well. I have 2 Parallels that are 1/4" thick x 1 7/8" x 6" and they work great. I use them exactly as Stan described.

Humvderby wrote:Thanks for the clarification. In regard to using them to drill axles holes, as Stan just pointed out you can clamp the block between two Parallels and they work very well. I have 2 Parallels that are 1/4" thick x 1 7/8" x 6" and they work great. I use them exactly as Stan described.

I hadn't considered using them to sandwich the block. It seems that it would be a bit more challenging to get it all clamped up while each parallel is maintaining contact with the drill press table.

Stan Pope wrote:1-2-3 blocks would need to be used in pairs in the form of a 1-2-6 block.

Yes, that is what I think as well. Or just get a single 2-4-6 block, but you would need a clamp with a bigger throat.

It's a means of drilling a determinate angle by placing a block on your drill table and inserting a spacer between the bottom of your piece to drill and the block, so that the drilled piece is held at an angle.

Stan Pope wrote:
ProBody Tool:
+ Eliminates the "nonparallel sides" issue.
+ Hole trueness much less dependent on "good drilling technique."
+ Requires NO drill press.
- Single application tool, but priced so that the single app is much less of an issue.
- Subject to much more "wear degradation" than other tools in the list.
- Capable of "positive camber" only in special situations (thin body so the work piece can be inserted upside down).

The Probody tool and all the other jigs like it that have a drill bit guide aren't precision machined to the size of drill bit used and will allow for enough slop to cause misalignment. When I first started diving into cub scout derby I didn't have a drill press and I bought a ProBody jig. The bit wiggles easily in the guide holes and we did have a toe alignment problem. I don't feel that it performs the first two positives very well. It is a cheap tool that can help over hand drilling or using axle slots but it is nowhere near as accurate to using "the Block", "Silver Bullet", or other machined square blocks when comparing those same pros. I would also argue that the hole trueness is no more dependent on good technique using the block then using a Probody jig. I will concede that using a drill press may take a little more know how then a hand drill but it does most of the work for you. All you have to do is line up your mark and pull the lever down.

Goatboy has made and sold a precision cut steel jig with hardened bushings for the drill guides that hold a #43 drill bit snug he made it with a pair of canted guides and a pair of straight guides. The price to make that high end of a tool makes it pretty cost prohibitive for an average scout builder. Even with the hardened bushing it will eventually wear enough the bit will start to get wiggle in the guide holes.

ngyoung wrote:Most of the cost is in the hardened bushings. They're usually over $10 a piece from what I have heard.

The machine I used, took hardened steel rod. Turned it down to size needed for wholes. Drilled them strait and a alignment notch. Then did 1 or two other sets of two. With different cant.

Its more if buying a rod, hardened for $12 from Fastenal. Then having a jig to hold the smaller size rod. In place while milling machine, used kind of as a drill to do the wholes.
Least that's how I seen them make it.

Old hard ended steel ejector pins, were used for the sliding adjustment, spacing of the aluminum blocks. They got tons of them. They picked up at factory closings.

It had a locking set screw to hold in the hardened steel bushings. I had the set screw and two bars for adjustment in a little bit different place.

If you look closely you will see another whole, but not all the way thru. I could either keep the other canted bushings in the whole or, take it back and have it drilled out all the way to have the higher up axle wholes. the axle whole height was the same as the derby worx pro body jig.

I sold it, But I liked it, but I did find issue with it. I would dull the drill bits, why ? well drilling canted, even with a hardened steel bushing, but I was drilling with a drill press. I dried a hand drill and that was worse,

Just because you have a bushing, guide. Does not mean the drill bit wont bend or wander once past the bushing or guide. once into the wood. the drill bit cans till flex and bend. now drilling strait, I did not have issue. But drilling canted, was harder to do with bushings with a drill press or even harder with a cordless drill.

Main reason, I still feel, you have to cant the whole piece of wood and let the drill bit, drill strait.

the problem with this tool- The silver bullet, It does a great job at angle, better then my smaller angle adjustment tool, because of the size. and drifferent size rods, can do different cants. its nice in all those things.

The main problem, why I don't use it. Is because its one issue over the other.

I still got wondering drill bit and not true axle whole drilling.

When I first start to drill at a cant, that drill bit is hard to line up. it wants to flex a little, move a little. that very first instance of touch to the wood, is so important.

That's why its so hard for kids to do drilling cant well. its not easy ! And you need a really good drill press, don't have much run out or wobble.

Its not a fault of the tool. Its the correlation ship between a few tools needed to do two things very well, working together.

I always get hammered for this, But Im just being so honest and, so many in private, agree.

its a nice tool, its just still needs another piece of the puzzle, if you want great canted axle wholes drilled.

And So I worked on tinkering, to find what was really the best for me, with a average cheap $60 drill press. And I found two things that worked great for me.

One, why couldn't I just used the pinewood derby block of wood and a drill rod with different sizes and tape the drill rod onto the block of wood and use that to cant.

well bingo, so Im like, I don't need the other tool. sure still need to make sure you got a true piece of bsa wood.

But I still have the same issue, drilling canted.

and the pro body jig, well. it worked easy for me, to use to drill start wholes into the wood. 1/16th deep. sometimes by accident a little more.

and bingo, no drill bit slipping and my accuracy for drilling cant, went to being pretty darn good.

And I kept trying to think, could I find something else to work better and that I could do without and still get good results.

And I found I could do without the silver bullet and just use a drill rod and some tape and use my wood. to do the cant. $3 for drill rod.

But I could not find anything that would give me good starter whole. I have come to totally rely on and use the pro body jig for the starter wholes.

starter whole. used the pro body jig.

And I drill my right front opposite cant, starter whole.

I still used a lighter canted axle for adjustment for drift.

right front cant

it's just the one tool, I cant go without. I know we all have are views and different tools that work for each of us. I wanted to bad the $60 plus silver bullet to work for me, I really did. But in the end for me, I could do the same thing with a drill rod, some tape and the wood.

But I couldn't find any thing else out there, that would give me a good accurate starter whole and be adjustable or do strait drilling for non canted axle wholes.

I mean you see me other tool I had made to try and do both. I mean I put allot of time into trying things and trying to do better.

If I had a proxxon drill press, then maybe the story would be different. But I don't and cant afford one.

From a person who wanted to build good cars, teach his kids how to do it, and what was the easy and best way I could find, esp when helping or running pinewood derby work shops. and how much of it can I have the kids do !

The only thing we don't let the kids do, is use the saws to cut the wood.

I use a pin vise when drilling with the Goatboy jig and have had good results. I guess I don't notice any wandering when I have used the SB. I have a cheap harbor freight bench top one as well and all the cars I have drilled using it went through like a hot knife in butter. Jamming the drill into the wood will cause problems no matter what tool you use.

ngyoung wrote: Jamming the drill into the wood will cause problems no matter what tool you use.

Tell me about it!

After having tried the method to Sporty's (madness) as well,
and having tried using the other unmentioned tools as well.................
Please excuse my bad drawings and illustrations to the method behind his madness
(as it is this vs this.)
Not saying one will use too much pressure on the drill bit while drilling but if one does,
and is not holding down on the tool while drilling this could teeter totter.

Now to Sporty's, maddness..

Last edited by whodathunkit on Sat Oct 04, 2014 9:46 am, edited 1 time in total.